Messages - NinthPlanet

How would we have an immunoglobulin E that reacts to an alien we have never encountered before?

Your body produces vast numbers of antibodies with subtle variations in their binding structures generated through a mechanism called Somatic Hypermutation - including many that react to no known analog in nature (at least on this planet).

As well, there's more than one pro-inflammatory pathway that can trigger the excess of Histamine required for a lethal reaction - though most are perceptibly slower.

Perhaps by an anomalous Cytokine response triggered by alien proteins that were (by a mathematically improbable coincidence) similar to those of an earth parasite? You'd only have to inhale a couple of pollen spores for an immune response to begin, so naturally consuming a portion of some xenofood would make it much worse as you'd have lots more proteins to react to & only emesis to remove them from your stomach (not to mention the damage to your intestinal flora, which you need to absorb several essential nutrients).

It might not be as spectacular as the Type 1 Hypersensitivity that someone allergic to peanuts would experience on eating some peanut butter, but the end result would be just as unpleasant, and deadly.

If some day we managed to travel to another planet, and discovered aliens, what is the likelihood that we could eat them?

What do you think?

People have already mentioned Molecular Chirality & noted that most of earth's organisms use (& can only process with Enzymes) Left (L) Handed chirality. I did want to mention that Right (R) Handed molecules do show up occasionally, they just can't be properly processed by our Left Handed Enzymes. Also, R molecules taste sweet to our taste buds, so R-based Alien life forms could be tasty, just indigestible.

The aspect of Alien Life that hasn't been mentioned yet is the probability that it could trigger an Immune Response & even Anaphylaxis. Even a single bite could cause your immune system to go on the warpath, attacking everything in sight - eventually causing your lungs to fill with fluid & your throat to swell closed, quickly killing you.

The Color of Distance by Amy Thompson is a science fiction novel that addresses some of the difficulties of visiting alien worlds. In the book, humans must live in completely sealed off from the xenobiology, as the slightest contact with any of the local environment will trigger an intense immune response (Anaphylaxis) that would potentially be lethal.